Weird Animal Brain: Octopus

The octopus almost reaches alien status when it comes to its brain and nervous system.  And yet, the differences can help us understand more about the human brain as well as unique solutions nature has come up with for difficult problems like camouflage.  Octopuses can see polarized light, but cannot see color.  However, their skin changes both color and texture to camouflage with the surroundings.Continue reading

The Departure of Skill Memories from Motor Cortex: Deeper Directions for Neuroscience

You probably have certain skills that I don’t.  Each of us, having spent enough time practicing something new, can become an expert.  A simple, ubiquitous example is driving a car with a manual transmission.  The precise sequence and timing of controlling the clutch, giving gas, and shifting the gears are challenging to coordinate when initially learning to drive a stick shift.  But eventually, the precision with which we can perform these sequences of movements is impressive.  Specifically, the errors we make when learning, indicated by gear grinding and stalling, are reduced with repeated practice.  Skill learning is relatively easy to train both in humans and in animals.  It therefore serves as a great way to study how the brain forms memories and uses those memories in the future.Continue reading

Zebrafish

What Zebrafish Teach Us About Touch

Unlike the sense of vision, which is perceived only by light-sensitive photoreceptors in our eyes, the mechanoreceptors that respond to light touch are located in sensory neurons all over the body.  Our sense of touch starts in the skin, where sensory neurons with elaborate dendrites just below the skin’s surface provide dense coverage over the entire area of the body.  When we touch something, the mechanical pressure created by the contact between an object and our skin opens mechanoreceptors that cause the sensory neuron to fire an action potential and activate downstream neurons.  We are constantly coming into physical contact with objects and people in our environment, and as a result a large number sensory neurons are being activated over many different areas of our body at any given moment!  How does the nervous system handle all of this incoming tactile information?Continue reading

Itching to Understand Dynorphin Knowing Neurons

Itching to Understand Dynorphin

Bzzzzzz!  Splat!  Ugh!  Anyone who has ever been around a campfire during the summer months is familiar with this progression of noises.  Mosquito bites and the resulting welts provide unwelcome souvenirs of time spent outdoors.  We all know we shouldn’t scratch.  Itch like pain is an aversive stimulus that alerts us to threats to the body.  But when the itch becomes too unbearable, we all give in.  Scratching is designed to remove irritants from the skin (at least temporarily), but don’t be fooled by this instant gratification!  Scratching causes tissue damage that increases the severity of the itch by releasing inflammatory particles.Continue reading

Taxi Photoswitch Knowing Neurons

Turning On A “Photoswitch” Helps Blind Mice See The Light

Our senses connect us to the world.  Your visual system lets you know that there is a yellow car ahead of you, and your auditory system lets you know that it is honking its horn.  As unique as each sensory system seems, they actually share basic characteristics and similarities of structure and function.  Beginning with a stimulus (the vision of the car or the sound of the horn), a cascade of complex interactions occurs that send signals through neural circuits so that we can respond to our surroundings.Continue reading